Watching quake-made lakes

A Wairarapa business is doing more than you would think in helping Kaikoura stay safe from its environmental impacts post-earthquake.

Masterton telemetry business Harvest Electronics has been contracted by NZTA to monitor the levels of the two lakes above Goose Bay and the Hapuku Lake, both formed after the November earthquake.

The system will provide an early warning system to NZTA and road users if the dams burst.

The magnitude 7.8 earthquake created a 150-metre landslide, that dammed the Hapuku River 10km from Kaikoura.

Goose Bay, which is 15km from Kaikoura, was previously evacuated due to concerns about the landslip blocking the Ote Makura Stream.

Harvest Electronics designs and manufacturers its own remote monitoring equipment which allows them to respond quickly to situations such as the earthquake.

One of the company’s technicians was flown down to the Hapuku Ranges on December 14, and to Goose Bay on December 23, by Jason Diedrichs of Amalgamated Helicopters.

Peter Munn, Harvest Electronics managing director, said they had done many similar projects across the country including a lot of work for KiwiRail monitoring tracks.

“If the Hapuku dam were to burst it would take out the road below it,” he said.

“However, the dam at Goose Bay is more serious because it could take out the settlement below of about 15 to 20 houses, and the road bridge.”

Historically, based on overseas events, the naturally made lakes and dams could burst within a month of forming.

However, readings of the dams’ water levels are taken every minute along with pictures, and the data is sent to the Masterton base.

“The monitors installed have alarms and a depth sensor, and if the dam levels drop by about half a meter, the alarms will sound and the system will trigger the siren at Goose Bay, and people will have about two to three minutes, four minutes maximum, to get to higher ground,” Mr Munn said.

They will install another system 10km inland from Kaikoura this month.